The present invention generally relates to a filler ribbon for placement on top and/or bottom portions of a ribbon stack in a buffer tube.
In related buffer tubes, grease is provided in the tubes to reduce fiber attenuation of the optical fibers in a ribbon stack. The grease helps reduce water penetration, and adds cushion between the ribbon fibers and the buffer tube. When using grease, however, a clearance must also be provided between the top and bottom ribbon and the buffer tube, to reduce contact between the fibers and the buffer tube. Other materials used in related buffer tubes include foam layers, water blocking tape, gel and yarns.